The president of the Highland Park Little League, Brent Stanton, was a witness to the event. He said Winninger was driving close to 40 miles per hours and was intentionally trying to hit people.

"I was up here getting equipment ready to start working the fields and everything went crazy," he said. "He ran over a gentleman then crashed through the fence and lost control, then crashed into the concession stand."

Two people were injured in the incident, 49-year-old Dean Bradham of Sioux City and 56-year-old Edwin Sullivan of West Des Moines. Sullivan is in critical condition at a local hospital. Bradham was treated and released at the scene.

Stanton said the Steamfitters Union rented out the ball fields the Saturday night before and they came back Sunday morning to clean up, when the incident took place.

Winninger remains hospitalized for treatment of his injuries.

Officials aren't releasing any information on what may have sparked the incident. Their investigation continues.